There has been a technique for extracting a feature point from a video picture image-captured using a camera attached to a moving object and tracking the position of the feature point from time-series video pictures.
As an image processing method for tracking a moving object, the following method has been known. For example, in Japanese Laid-open Patent Publication No. 2010-039617, feature points are extracted from a video picture at first time, and small areas centered at the respective obtained feature points are set. As for a video picture at each instant of time at or after second time, matching utilizing the similarity (coincidence) of a video picture brightness pattern in each individual small area is performed, and thus, tracking of the feature point defined at the first time (a first method). Usually, the feature point is a corner point indicating the corner of an object in order to accurately perform tracking.
In addition, an image processing method (a second method) in which, as for a video picture at each instant of time of a time series, a corner point (feature point) is extracted in advance, a small area centered at the corner point is provided while targeting the corner point, matching is performed using the similarity of a video picture brightness pattern within the small area, and tracking is performed has been known.